Analysis of biopotential electrical signals generated inside the human body, for example for electrocardiography (ECG), electro-encephalography (EEG), and analysis of the response of biological tissue to imposed currents, for example for bio-impedance measurements, requires a good electrode-to-skin contact. Solutions such as gel electrodes may ensure a good contact between the electrode and the skin with the use of conductive gels. These gels, however, require application before measurements and removal after use, and tend to dry out over time, making them cumbersome and unsuitable for certain applications, such as long time monitoring.
Alternatively, known dry or dry-contact electrodes are currently available in the form of electrodes with rigid pins that are pressed onto the skin. Their rigidity, however, makes such electrodes uncomfortable to wear and prone to motion artifacts. There has been also some interest in developing conductive polymer electrodes, such as the ones described in “Comb-shaped Polymer-based Dry Electrodes for EEG/ECG Measurements with High User Comfort”, by Y. H. Chen et al., IEEE Engineering in Medicine and Biology Society (EMBC), 35th Annual International Conference of the IEEE, pp. 551-554, Osaka, Japan, Jul. 3-7, 2013. Although such electrodes present promising results, their conductivity is still low for certain applications.
There is a motivation to improve current state of the art dry electrodes in order to improve user comfort, setup time, and/or high quality biopotential measurement.